A health supplement business is being investigated in connection to a nation-wide drug syndicate accused of dealing in methamphetamine and illicit pills sold as ecstasy.

Police and forensic scientists today conducted a scene examination at High Performance Health, a business on Carlyle St in Sydenham, Christchurch, following a raid.

Investigators have examined a commercial pill-press and pills found inside the business on Carlyle St. They have also uncovered 5 kilograms of an unidentified white powder, thousands of suspected illicit pills and a shotgun and ammunition in a lock-up near Christchurch Airport.

Police say the investigation is ongoing.

The company's sole director Hugh Robinson, 58, and his son Jamie Robinson, 26, have appeared in Christchurch District Court facing drug charges.

Jamie Robinson has been charged with supplying and conspiring to deal methamphetamine and a Class C drugs, while Hugh Robinson is charged with possessing and conspiring to deal a Class C drug.

Connected to major drug syndicate

Police raided the business in connection with an operation to bring down a major drug syndicate, which has been producing and selling tablets as ecstasy.

Thousands of tablets sold as ecstasy, a commercial pill press, guns and nearly $2 million worth of assets have been seized from a major drug syndicate.

Nearly two dozen people have been arrested after raids at 20 properties in the Canterbury, Wellington, Bay of Plenty, Eastern and Central police districts in the last two days as part of Operation Nebraska.

Fourteen men and nine women, aged 21 to 61, will appear in courts across the country on serious drug dealing, money laundering and fraud-related charges.

Those arrested were part of a syndicate distributing methamphetamine (P) and ecstasy between the Bay of Plenty and Canterbury, police said.

Nine-month-old baby found at drug house

A 9-month-old baby and other children were found at some drug houses and referrals have been made to child youth and family.

Police have seized assets worth more than $1,875,000 including: four properties in Rotorua, Waikanae and Wellington, a boat, five cars and $235,000 held in a bank account.

Guns - including a shotgun and ammunition - were found during raids in Rotorua and Christchurch.

Detective Senior Sergeant Tim Leitch said police had monitored the syndicate for the last three months ''after a person came to our attention''.

The alleged king-pin of the syndicate was based in Wellington, who allegedly sourced methamphetamine from Waikanae and supplied it to Christchurch in exchange for pills, which were then distributed in the North Island.

"Everything centred around him," Leitch said.

The pills were sold as ecstasy, but a significant number likely contained benzylpiperazine (BZP).

"There's been a lot of movement ... of cash. We are still trying to unravel the extent of the laundering."

Operation will disrupt drug market

The operation involved more than 100 police, including the armed offenders squad, and would cause "significant disruption in the illicit pill market".

"We are sending a clear message to these people that if you are going to derive your income from drug activity that harms our communities, we will be using all the legislation available to us disrupt that behaviour and seize those assets."

The raids come after police smashed a sophisticated criminal network and seized more than $2 million worth of methamphetamine in Wellington, the Hutt Valley and Horowhenua last week.